1. Field of the Invention
The present invention relates to an electron-emitting device and an image display apparatus as well as an electron source therewith. In addition, the present invention relates to an information display and reproduction apparatus such as a television set and the like for receiving signals of a broadcast such as a television broadcast and the like and for displaying and reproducing video information, text information and audio information included in the broadcast signals.
2. Description of the Related Art
Conventionally, there known as an electron-emitting device are surface conduction electron-emitting devices disclosed in Japanese Patent Application Laid-Open No. 2000-231872, Japanese Patent Application Laid-Open No. H01-112633, Japanese Patent Application Laid-Open No. H01-093024, Japanese Patent Application Laid-Open No. H10-050208 and Japanese Patent Application Laid-Open No. H09-330649. An example of a process of making a surface conduction electron-emitting device will be described below with FIG. 15A to FIG. 15D.
At first, a pair of auxiliary electrodes (2 and 3) are formed on a substrate 1 substantially having insulation properties (FIG. 15A). Subsequently, the pair of auxiliary electrodes (2 and 3) are connected with electroconductive film 4 (FIG. 15B). Japanese Patent Application Laid-Open No. H09-330649 has disclosed electrically conductive film 4 comprising Ni and Ni oxides with Ni in the Ni oxides being not less than 5 atomic % and not more than 90 atomic % of the entire Ni in the electroconductive film 4. In addition, as the Ni oxides, NiO and Ni2O3 are disclosed as the Ni oxide. In addition, it is also disclosed that the electroconductive film 4 is configured by fine particle film.
In addition, by applying a voltage between the pair of auxiliary electrodes (2 and 3), an operation of the part of the electroconductive film 4 undergoes a process called “energization forming” of forming a first gap 7 (FIG. 15C).
The “energization forming” operation is a process of causing a current to flow in the electroconductive film 4 to form the first gap 7 in the part of the electroconductive film 4 with Joule heat attributable to the current. That “energization forming” operation makes it possible to form a pair of electrodes (4a and 4b) facing each other with the intervening first gap 7. And, preferably, an operation called “activation” is carried out. The “activation” operation typically includes a process of applying a voltage between the pair of the auxiliary electrodes (2 and 3) in a gas atmosphere containing carbon. That process forms electroconductive carbon films (21a and 21b) on the substrate 1 inside the first gap 7 and on the electrodes (4a and 4b) in the vicinity of the first gap 7 (FIG. 15D). Consequently, a second gap 8 defined by the gap between the first carbon film 21a and the second carbon film 21b is formed inside the first gap 7. The “activation” operation occasionally can improve electron-emitting performance compared with an electron-emitting device formed only in the “energization forming” operation. The process described above forms an electron-emitting device.
An image display apparatus can be configured by causing an electron source composed of a plurality of the electron-emitting devices and a substrate comprising light emitting member film comprising a phosphor and the like to face each other and retaining the space between them at pressure (typically in vacuum) lower than the atmosphere pressure.
FIG. 16A is a plan diagram schematically showing the electron-emitting device after having undergone the above described “activation” operation. FIG. 16B shows schematically section along the 16B-16B line in FIG. 16A and is basically the same diagram as FIG. 15D. On the occasion of causing the above described electron-emitting device to emit electrons, potential applied to an auxiliary electrode (2 or 3) is made higher than the potential applied to the other auxiliary electrode (3 or 2). Thus applying a voltage between the auxiliary electrode 2 and the auxiliary electrode 3, an intensive electric field is generated in the second gap 8. Consequently, it is understood that electrons are emitted from a large number of points (a plurality of electron-emitting sites) of a portion being an end circumference of the carbon film (21a or 21b) connected to the auxiliary electrode (3 or 2) on the low potential side, configuring an outer circumference of the second gap 8.